Discovery of the Ice Man

The story of the ice man illustrates how the double helix structure of the DNA molecule gives it an incredible stability and longevity.

In 1991, tourists hiking in the Alps, on the border between Austria and Italy, spotted a corps, trapped in the ice. Alongside the body, a copper ax, dagger and a quiver with several arrows were found. Several unsuccessful attempts to free the body were made by the local residents. Four days after the discovery, on September 23th, a team of forensic experts arrived to recover the body and transport it to the University of Innsbruck. It was there that the corpse, in the mean time renamed as ‘ice man’ was refrozen and subsequently subjected to scientific study.

Age, Origin and DNA of the Ice Man

Through the use of radiocarbon dating, the ice man was deemed over 5000 years old. Recent evidence seems to suggest that he was shot in the chest with and arrow, and died soon after the wound was inflicted. The cold, high-altitude air led to the dehydration of the body, which was covered by snow that turned into ice, remaining frozen for over 5000 years.

At the time, there were some experts that questioned the ice man’s origin, claiming it was a hoax involving some South-American mummy that was placed in the Alps. To determine the authenticity and origin of the ice man, tissue samples (muscle, connective tissue, and bone from his left hip) were taken and DNA was extracted from these. Through PCR (polymerase chain reaction), small regions of DNA were amplified. The base sequence was determined and compared to the sequences of modern-day human beings.

Results of the Analysis

The ice man’s DNA sequence resembled the one that can be found in modern-day Europeans living north of the Alps. Combined with the radiocarbon dating and the artifacts, this led to the conclusion that the ice man was a Neolithic hunter who died in an attempt to cross the Alps over 5000 years ago.

The fact that some of the ice man’s DNA persisted is a testimony to the remarkable stability of the molecule with the double helix. Today, even Neanderthal DNA has been isolated from fossilized bones, over 30,000 years old.

So, the double helix structure does not only look elegant, but also improves the stability of the molecule, allowing us to investigate the past in more detail than we imagined.